Process of reduction of ores containing sulfur and iron.



"UNITED STATES rnrENT OFFICE.

ARNOLD WIENS, 0F BITTERFELD, GERMANY, ASSIGNOB TO ELEKTBOCHEMI SCHE WERKE, G. M. B. H., OF BERLIN-BITTEBFELD, GERMANY.

PROCESS OF REDUCTION OF ORES CONTAINING SU LFUR. AND IRON.

No Drawing.

To all whom it may concern:

Be it known that I, ARNOLD Wrens, a subject of the King of Prussia, residing at 19 Lindenstrasse, Bitterfeld, Germany, have invented a certain new and useful Process of Reduction of Ores Containin Sulfur and Iron, of which the following is a specification.

The direct reduction of iron ores containing sulfurhas hitherto not been possible as the products obtained were unusable because of the resence of sulfur. Even the conversion 0 ores containing suifur into compounds of iron, such for'example as ferrosilicon, has hitherto not been carried in effect.

lVhen using sulfur 'ores for the production of ferro-silicon a product containmg a large amount of sulfur is obtained even in electric furnaces, when the content of silicon' is relatively low. It was therefore notto be assumed that this relationship would vary, if the content. of silicon was increased.

Numerous researches have however given the surprising result, that after the content of silicon has increased above a certain amount, the content of sulfur is decreased to a minimum, so that according to this process a product is obtained wnose low content of sulfur meets therequirements of marketable goods in every manner. Naturally the effect in e ectric furnaces.

It is sufficient, for the purpose of reducing the sulfur to minimum, to add to the raw material so much sill'c'ic acid, that the re-.'

sulting ferro-siliconcontains 20% Si. If less quantities are use sulfur increases in th the content of silicon,

an'ie proportion as 111 the ferro-s llcon formed, decreases. For example when obtaining a fcr1osilicon-.

With (3.4% silicon 3.1% sulfur is pre sent'.

:4 23g? 44 u u c I U o 22.0% f 0.12 3151. 1,. no sulfur is present.

When carrying the process into effect care must be taken that a suflicient quantity of silicon is always formed to drive out or displace the sulfur inthc ferro-sulfuret, or iron containing sulfur. It isimmaterial whether the silicic acid is present in the ore used or whether this is added artificially. The stil- Speclflcatlon of Letters Patent.

Application filed February 27, 1909. Serial No. 480,386.

rocess can only be carried into.

hen the content of substantially eliminate the su Patented Oct. 25, 1910.

fur displaced in the iron then escapes and if the process is carried out in a closed furnace it can together with the carbon dioxid, formed by the reaction be distilled over' into receivers and there coiidensed or used for other urposes. I

If tie ores contain other metals besides iron such for example as zinc, which is ve often the case in common iron pyrites, it is essential that the material should be first roasted; substances are thenadded thereto,

with which the remaining sulfur that is set free combines without being additionall driven oil either by carbon or by-silicic'aci By these means the zincis recovered in receivers in the metallic form or as oxid but without sulfur. Lime is generally used as such a sulfurabsorbing substance. It is immaterial whether it is previousl contained in the ore or whether it is adde afterward. Other non volatile metals can then be removed besides the ferro-silicon.

From the foregoing it will be seen that by means of this process ores, the reduction of which Was hitherto impossible can now be converted into ferro-silicon and the like. The waste pyrites containing zinc and sulfur which remained from the manufacture- Zinc ores-that are only reduced with difliculty can be added to the iron ores asin principle, it isimmaterial whether oxidized or sulfurized ore predominates. Further it is of the eatest importance in the usefulness of t e-.process that since the 'electric furnace is entirely'closed a .very pure. carbonic acid gas is obtained under the; circumstances.

What I claim as my invention and desire to secure by Letters Patent p 1-. The method of reducing ores contain ing iron and sulfur, which consists in smelt mg the ore to ferro-sihcon 1n the presence of silica and carbon and: at a high temperature by the aid of an electric current, he uantity as to;

silica present being in such furfrom" the ferro-silicon scribed. r

produced; substantially s de- 2. The method of reducing ores containing iron and sulfur, whichconsistsfin roasting the ore to partially desulfurize it,

then smelting the roasted ore to ferro-silicon inthe presence of silica and carbon and at a high temperature with the aid of an electriccurrent, the silica being present in such quantity as to substantially eliminate the sulfur from the ferro-silicon produced; substantially as described.

'3; The method of reducing ores containing iron and sulfur, and which likewise contam other volatile and non-volatile metals, which consists in smelting the ore to ferrosilioon in the presence of silica and carbon and at a high temperature with the aid of an electric current, the silica being present in such quantity asto'zs ubstantially eliminate the sulfur from the ferro-silicon produced retaining the sulfur in the slag by a suitable sulfur absorbing element of said slag, rc-

covering the volatile metals by distillation and condensation and recovering the non volatile metals with the ferro silicon; sub stantially as described.

In testimony whereof I have hereunto signed my name to this specification in the presence of two subscribing witnesses.

ARNOLD YVIENS.

Vitnesses:

JULIUS RUn'ni aN-D", OSKAR SINGER?" 

